Neutron Irradiation Induced Effects In Zircaloy-2

Abstract

Zircaloy-2 samples which have been neutron irradiated to doses of ~20 dpa at 690K have been examined. The observations show that the pre-existing precipitates undergo irradiation-induced dissolution and solutes segregate to grain boundaries to form irradiation-enhanced precipitates and solute concentration gradients. The irradiation-induced dislocation structures in the matrix consist of dense loop and network dislocations, having Burgers vectors, b=1/3<1120>, as well as a high density of c-component dislocations. The significance of these observations is discussed in terms of current theories of neutron damage and irradiation growth of Zircaloy-2.